Earlier this year I heard University of North Carolina (UNC) at Chapel Hill doctoral student Ryan Kingsbury, a member of Orlando Coronell’s lab discuss his research and was introduced to the term “blue energy” for the first time. Ryan studies energy storage and generation from salinity gradients. Salinity gradient energy or “blue energy” refers to the energy released when water with different concentrations of salt mix (this is essentially the reverse of what happens during desalination). For those of you who teach about diffusion, here is an opportunity to show your students how selective diffusion of positive and negative ions across membranes can drive the production of electricity!
Salinity gradient energy is at the cutting edge of research on renewable energy. Using ion-selective membranes and a process known as reverse electrodialysis (RED), natural and industrial waters (e.g. seawater, desalination brine, etc.) can be used to store energy, generate electricity and even treat wastewater! Ryan recently described the physics behind blue energy and RED in a bit more detail in his own blog post.
And now for the pickle part. It turns out one of the industrial wastewaters being investigated by researchers is the leftover salt water from making Mt. Olive pickles! Researchers from NC State University, UNC-CH, East Carolina University and the Coastal Studies Institute are developing a process that uses salinity gradient to release energy from Mt. Olive wastewater. There is a 6 minute video describing this multi-institutional collaboration and a transcript of the video also available. The project PIs (Dr. Coronell from UNC and Dr. Call from NCSU) also participated in a February 2016 radio interview about salinity gradient energy which explains their project more broadly.
In addition to pickles, NC is also known for its estuaries; the mixing of salt and fresh water that occurs in estuaries is an untapped source of blue energy! In fact, I learned from reading Ryan’s blog post that where rivers flow into the sea and fresh and salt water mix, the amount of energy created is equivalent to the river falling into the ocean from the height of the Eiffel tower!
You can also learn more about blue energy in this June 2015 BBC article Blue energy: How mixing water can create electricity.
With the 2016-2017 school year now underway, I wanted to be sure you knew about a new resource from the US Department of Energy’s Office of Energy Efficiency and Renewable Energy – a monthly electronic newsletter titled STEM Spark – that will highlight energy technologies, energy education resources, career information and competitions for K-12 and higher education audiences.
The August 2016 newsletter is devoted to the topic of wind energy.
Click here to subscribe to the monthly newsletter.
Published November 2, 2015
Coal , Energy - General , Energy and the Environment , Fossil Energy , Geothermal , Lessons and Activities , Maps , Natural Gas , Nuclear Energy , Renewable Energy
I recently learned about the American Geoscience Institute’s (AGI) Critical Issues Program, a “portal to decision-relevant, impartial, expert information from across the geosciences.” This website is a potential place to look when you are searching for information related to issues at the intersection of geoscience and society, including energy, climate, water, mineral resources and natural hazards. In fact,writing that last sentence also made me think of recent commentary I read titled “Why I am a geoscientist” in which the author, Erig Riggs, PhD, states that he loves being a geoscientist because it is an “area of science so directly relevant to the public.”
Energy topics covered include coal, geothermal energy, hydraulic fracturing, mineral resources, nuclear energy, oil and gas and renewable energy. The “Basics” section for each energy topic includes a brief summary that also describes why this topic matters to society and that explains how geoscience informs decisions about the particular topic. The “Learn More” section includes links to introductory resources, frequently asked questions, related maps and visualizations along with references. Resources featured come from the US Department of Energy, Energy Information Administration, Geological Society of America, The National Academies and USGS and others.
Furthermore, AGI offers three earth science focused activities aligned to the Common Core English Language Arts standards and the Next Generation Science Standards that can be used to prepare grades 6-12 students to read and evaluate informational text.
Want to learn more? Check out AGI’s Center for Geoscience and Society.
Published October 9, 2015
Biomass , Coal , Data Visualizations , Electricity , Energy - General , Energy and the Environment , Geothermal , Hydropower , Infographics , Interactive , Natural Gas , Nuclear Energy , Petroleum , Renewable Energy , Solar Energy , Transportation , Wind Energy
The World’s Energy System in 2012
The International Energy Association’s publication Energy Technology Perspectives 2015, is accompanied by a set of interactive visualizations that utilizes the data and figures behind its publication on energy technologies. I am an advocate for having students visualize the entire energy system – the diversity of energy sources used to provide electricity to homes and industry and to power our various modes of transportation. I also find it useful to examine how the system is changing over time as our demand for energy grows in light of the need to limit society’s carbon dioxide emissions. These interactive infographics from the IEA illustrate how the world’s energy system will evolve through 2050. There are three parts to this online tool: an energy flow visualization, an emissions reduction visualization and a transportation visualization. Here I am featuring the energy flow visualization where the user can hover over a specific energy source, transformation or end user to study a particular energy flow. The diagram below shows the global energy flow for coal in 2012 and for 2050 (projected); one can easily compare the two graphics to see that coal use will decrease while global energy demand will increase. Have you considered asking your students to evaluate and explain energy flow diagrams?
Global energy flow for coal in 2012 and for 2050 (projected).
The emissions reduction visualization tool allows the user to assess how individual countries or regions can reduce carbon dioxide emissions via deployment of technologies and energy efficiency measures under three different warming scenarios (2°C, 4°C and 6°C). The transport visualization tool enables the user to select an “indicator” such as annual road energy consumption for a specific country, region or the world to visualize the extent to which the selected indicator needs to change to limit Earth’s average global temperature to either 2°C, 4°C or 6°C. According to the IEA website. “the 2°C Scenario is the main focus of ETP 2015. It lays out the pathway to deploy an energy system and emissions trajectory consistent with what recent climate science research indicates would give at least a 50% chance of limiting average global temperature increase to 2°C.” You can read the Executive Summary of the ETP 2015 here.
And if you want to read more about energy flow diagrams, check out this post.
Published September 28, 2015
Biomass , Capturing Carbon , Coal , Electricity , Energy and the Environment , Energy Efficiency , Fossil Energy , Hydropower , Interactive , Lessons and Activities , Natural Gas , Nuclear Energy , Renewable Energy , Solar Energy , Wind Energy
I recently learned about this interactive online “Energy Challenge” by Duke Energy where users create a plan to meet the energy demand of a carbon constrained world in the year 2050. Duke Energy aggregated data from across its entire U.S. service territory and created a visual representation of its service area and power generating facilities which sets the stage for the user who is tasked with making choices about how to meet a growing energy demand while working towards CO2 reduction goals. Choices that can be made by the user include: building new power plants, including solar and wind farms, upgrading existing power plants to produce more energy, retrofitting existing plants to reduce emissions, closing inefficient power plants and implementing energy efficiency programs.
As users make decisions, such as retiring a set of aging coal plants or adding a wind farm, they get instant feedback regarding cost (in billions of dollars), impact on CO2 emissions (tons per year) and the extent to which their plan meets the predicted energy demand for the year 2050. The energy demand meter displayed on the right side of the screen makes it easy to visually monitor the extent to which a decision helps to meet energy demand and the extent to which this demand is met through non-renewable energy sources, renewable energy sources and energy efficiency measures.
Duke Energy intends for this tool to “demonstrate the trade-offs and cost implications of choosing an energy generation mix that will meet future energy demand while minimizing CO2 emissions and keeping costs as low as possible.” I could easily see small groups of students competing to see which group can come up with a strategy that reduces CO2 emissions, meets projected energy demand for 2050 and costs the least amount of money.
To learn more about the game, click here.
One Indiana science teacher created a worksheet to accompany this game that could be used with your students.
If you have your students play this game, please share your experience by leaving a comment!
Published September 3, 2015
Coal , Data Visualizations , Electricity , Energy - General , Hydropower , Infographics , Maps , Natural Gas , Nuclear Energy , Renewable Energy , Solar Energy , Wind Energy
Earlier this summer the Washington Post published an online map (using data from the Energy Information Administration) to help users visualize the current state of electricity generation in the United States. In addition to showing electricity generation by energy source from January to May 2015, the location and capacity (in megawatts) of each power plant is also featured. Additional maps show the distribution of power plants utilizing a particular energy source (e.g., coal plants operating from January to May 2015).
I think lots of discussions could arise by studying maps such as these with students. Prompt students to consider how the sources of electricity that are used by a state or region are influenced by access to those energy sources. What do students notice about the distribution of coal plants? Natural gas plants? How might the observed trends relate to energy pricing, policies, etc.? One intention of the graphics is to show users that “Local electric utilities take advantage of the power sources most accessible to them: coal mines, dammed rivers, new supplies of natural gas or nuclear plants to generate the bulk of the nation’s electricity.”
Another interactive tool available let’s the user examine and compare how each state uses a particular energy source. For instance, with a single click the user can view the states that generate the most electricity from wind.
Published April 15, 2015
Electricity , Renewable Energy
I recently attended UNC’s Clean Tech Summit where I heard the term “microgrid” over and over when discussing the future of energy and the nation’s electric grid in particular. According to the US Department of Energy, microgrids are “are localized grids that can disconnect from the traditional grid to operate autonomously and help mitigate grid disturbances to strengthen grid resilience.”
The interest in microgrids continues to grow, in part, because of strong support from the Department of Defense (DOD). The 2015 Military & Government Microgrids Summit website states that “the DOD is establishing a network of microgrids at over 40 military bases, and are investigating the deployment of mobile microgrids at its 600+ forward operating bases.” Military leaders see microgrids as a component of energy independence and also a means to protect against possible cyberattacks. A June 2014 article describes how NC’s Fort Bragg is leading the way in the deployment of microgrid technologies.
And Duke Energy unveiled a microgrid test project in Mount Holly, NC earlier this year. According to a Feb 2015 article in greentechmedia, this project “will incorporate a solar- and battery-powered microgrid, capable of islanding from the grid for short periods of time and running on its own power. Unlike almost all the microgrids now running today, Duke [Energy]’s will have no backup generators or other spinning power resources.”
For those of you who teach about microgrids or want to update your instruction to include microgrids, I have compiled some resources that might be useful:
How Microgrids Work | Department of Energy
The Role of Microgrids | Department of Energy
Microgrid Activities | Department of Energy
Microgrids | Microgrids at Berkeley Lab (includes example of microgrids)
The U.S. Department of Energy’s Microgrid Initiative | The Electricity Journal
Smart Microgrids on College & University Campuses | Association for the Advancement of Sustainability in Higher Education
Please share other, related resources or activities that can be used to introduce students to microgrids and/or other ways to promote grid resilience.